Automatic door



A. P. NELSON AUTOMATIC DOOR June 14, 1932.

Filed May 20, 1929 2 Sheets-Sheet l A/VD Y IN VEN TOR. R A f/50M June 14, 1932. A, R NELS N 1,863,497

AUTOMATI C DOOR Filed May 20, 1929 2 Sheets-Sheet 2 j fidi, a

INVENTOR. ANDY 2/1 5450 Patented June 14, 1932 TENT OFFICE ANDY r. NELSON, or HURLEY, scorn DAKOTA AUTOMATIC noon Application filed May 20,

This invention appertains to closures and more particularly to doors of the sliding type.

One of the primary objects of my invention is to provide novel means for automatically opening a door by the weight of a person or vehicle approaching the door from either direction, the door acting to automatically close by gravity when the weight of the person or vehicle is removed from the door approaches.

Another object of my invention is to provide an automatic door to be used in stores, ofiices, or any public buildings, such as school buildings, churches, depots, hospitals or hetels, where the weight of pedestrians approaching the door, will automatically open the same and when said weight is removed to again close by gravity.

A further object of my invention is to provide a door frame, a pair of approaches, and a combination of levers and connecting rods, so constructed and arranged relative to the approaches and doors that with the application of weight to either approach, the doors will again close by gravity.

A further object of my invention is to provide an automatically opening door composed of a minimum number of operating parts, so simple in construction as to insure perfect operation.

A still further object of my invention is to provide an improved device for automatically opening sliding doors of the above character, which will be durable and efiicient in use, one that will be simple and easy to manufacture, and one that can be placed upon the market and incorporated with a building at a low cost.

\Vith these and other objects in view, the invention consists in the novel construction, arrangement and formation of parts, as will be hereinafter more specifically described, claimed, and illustrated in the accompanying drawings, in which drawings:

Figure 1 is afront elevation of a door con- 1929. Serial No. 364,580.

structed in accordance with my invention, the walls of the building not being shown;

Figure 2 is a detail vertical section taken on the line 2-2 of Figure 1;

Figure 3 is a horizontal section taken on the line 3-3 of Figure 1 looking in the direction of the arrows and illustrating the approaches;

Figure 4: is a front elevation of a slightly modified form of door which can be used for door openings of medium width the doors being shown mounted against the inner face of one of the frame sections;

Figure 5 is a similar View illustrating a still further modified form of door which can be used for relatively large door openings, and

Figure 6 is a detail section taken on the line 6-6 of Figure 1.

Figure 7 is a section taken on line 77 of Figure 1, looking in the direction of the arrow. Referring to the drawings in detail, wherein similar reference characters designate corresponding parts throughout the several Views, the letter A generally indicates my improved device, which comprises a frame 10 which can be incorporated in a building in any desired way. In the present instance I have illustrated a frame of simple type which may be used in pairs, one frame in front and the other frame in back of the door, merely to illustrate the working of my invention, and as shown, the frame 10 embodies side bars or standards 11, which are arranged inward and on each side of a door opening. The upper ends of the bars 11 can be secured to a top cross bar 12, while the lower ends of the bars 11 can be secured by a cross bar 13 or the same can be merely anchored in the building construction. The frame 10 illustrated, in actual practice may be duplicated and placed in a position to guide the doors 14 and 15 in their movement, or the usual door frame may be used to guide the tops of the doors 14 and 15, if desired.

Arranged between the side frame bars 11, for movement toward and from the same, is a pair of sliding doors 14 and 15 which normally meet at the vertical center of the doorway for closing the door opening.

In accordance with my invention 1 arrange on each side of the door opening novel approaches, which include platforms 17 and 18, the platform 17 can be disposed on one side of the door opening and the platform 18 can be disposed on the opposite side of the door opening. The outer ends of the platforms 17 and 18 carry pivot ears 19, which ears receive transversely extending pivot rods 20 which are in turn pivotally carried by the upper ends of short links 21 and these links have their lower ends rockably mounted on cross rods 22, which are secured in place in any desired way If desired, the platforms 17 and 18 can be arranged in a suitable way or frame which can be constructed of sheet metal or the like and this way or frame can include a bottom wall 23 and side walls 24, the upper edges of which incline upwardly toward the door to conform to the normal inclination of the platforms 17 and 18. l/Vhere such frame is used, the rods 22 can be anchored in the side walls 24 thereof.

The inner ends of the platforms 17 and 18 are provided with hinge barrels 25 which receive a hinge pin or rod 26, and this rod extends entirely through the side walls 24 of the frame at its opposite ends and said side walls can be provided with vertical slots 27 through which said terminals of the rod 26 extend. The walls of the slot 27 form a guide for the sliding movement of the pivot rodand prevents lateral shifting movement thereof. It

is obvious, however, that any desired type of guide can be provided for the rod. In the frame 10 illustrated, I have also shown inner door frame posts or plates 28, and these door frame posts or plates 28 can be connected to the bottom bar 13 and can also be provided with slots through which the terminals of the pivot rod 26 extend. The outer ends of the rod 26 are connected by means of a pin and slot connection 29 with the inner ends of links 30, which links are arranged on opposite sides of the sliding doors and the platforms 17 and 18 and in aplane below the lower edge of the sliding doors. These links 30 are rockably mounted at a point substantially equi-distantly their ends on brackets 31 which can be secured in the door frame in any desired way. In the present instance I have shown 34, which are pivotally connected at their angles, as at 35, to the side bars 11 of the frame 10. The long arms 36 of the bell crank 34 extend inwardly toward the outer side edges of the doors 14 and 15 and carry pivot pins 37 mounted in said sliding doors adjacent to the outer edges thereof. The levers 34 are arranged in inner and outer pairs, so that there will be a pair of levers on opposite sides of the doors.

When a person or any weight is on either one of the platforms 17 and 18, these platforms will be depressed which will cause the swlnging of the bell crank levers 34 on their pivots due to the connection of said bell crank levers with'the rod 26. A swinging of the bell crank levers will move the doors 14 and 15 away from each other toward the side frame bars 11, thus opening the door closures automatically. Upon the removal of the weight from the platforms 17 or 18, the doors are allowed to gravitate to their closed positions which will again raise the platforms 17 and 18 to their normal raised position ready for reactuation.

In order to further guide the doors in their sliding movement, I can provide guide links 39 which links are pivoted at their lower ends as at 40 to the side frame bars 11 above the upper ends of the bell crank levers 34 and the inner upper ends of the links 39 carry pivot pins 41 which are mounted in the doors 14 and 15 adjacent to the upper ends thereof. .The links 39, similar to the levers 34, are arranged in inner and outer pairs, so that there are are a pair of links on opposite sides of the door. By this construction, I provide four bell crank levers 34 and four links 39, which balance the doors perfectly without the aid of tracks and the doors have an upwardly and outwardly swinging motion when the plat-form is depressed. l Vhen weight is relieved from the platform the doors will gravitate, automatically, to their closed position.

. The particular type of bell crank levers 34 and the links 39 are especially adapted for relatively small doors and in Figure 4 I have illustrated a type of linkage for doors of "medium width.

the inner edges of the doors 14 and 15. The

extreme upper ends of the longarms 51 of the bell crank lever 50'carry pivot pins 52 which are slidably mounted in vertical slots 53 formed in the doors 14'and 15 adjacent to the inner edges thereof in relatively close proximity to the upper edges of the-doors. The doors in this arrangement will be opened in the same manner as'in the form first described and it is to be noted that the short arms 53 of the bell crank extend outwardly and terminate adjacent to the outer ends of the rod 26 and the outerv ends of the rod 26 are connected to the outer ends ofthe short arms 53 by means of pivoted links 54. Thus when the platform 17 or 18 is depressed, the rod 26 will be carried downward therewith exerting a pull on the bell crank levers and the same will rock on their pivots moving the doors to open position.

I11 order to further guide the doors in their sliding movement, I can provide guide links 55 which links are pivotally connected at their lower ends to the side frame bars 11 adjacent to their lower ends, as at 56. The upper inner ends of the guide links 55 carry pivot pins 57 which are slidably and rockably mounted in slots 58 formed in the doors let and 15 adjacent to the outer side edges thereof. These links are substantially in the same plane as the long arms 51 of the bell cranks 50. In this form also I provide inner and outer pairs of bell cranks and links and thus there are a pair of bell cranks and a pair of links on opposite sides of the door, forming an efi'ective means for supporting the door during its swinging movement.

In Fi ure 5 I have illustrated a still further modified form of linkage, which is particularly adapted for doors of relatively large width, such as garage doors, warehouse doors, and the like. In this instance the bell crank levers indicated by the reference characters 50, can be connected to the platforms 17 and 18 in the same manner as in the first form but relatively large bell crank levers are used and the long arms 61 thereof extend to the upper edge of the doors 14 and 15 and carry pivot pins 62 which are received in slots 63 formed in the doors adjacent to the outer corners thereof. The doors in this form are opened and closed in the same manner as the forms previously described, but it is to be noted that the upper edges of the doors can carry rollers 64 for engaging downwardly inc-lined trackways 65.

If preferred, door checks can be used so as to prevent slamming of the doors.

From the foregoing description, it can be seen that I have provided a simple device embodying a minimum number of parts for bringing about the effective and automatic opening and closing of sliding doors.

Changes in details may be made without departing from the spirit or the scope of the invention, but:

WVhat I claim as new is:

In a door opening and closing device, a supporting frame, a pair of sliding doors movable toward and away from one another, a pair of pivotal platforms leading toward the doors, said frame provided with inner door frame posts extending upwardly upon either side of and adjacent to said platforms for facilitating the holding of said platforms against lateral shifting movement, an operating rod passing transversely of said platforms and securing the adjoining ends of said platforms together, said rod projecting 

